This invention relates to the field of batteries, and more specifically to a button type battery that is safer for close contact with a person""s skin.
Illuminated jewelry is well-known, such as earrings that include small colored lights, such as light-emitting diodes, or LEDs Such jewelry is typically powered by a small battery or pack of multiple batteries.
Frequently, the jewelry is attached to the battery by long wires and the battery is attached to the person remotely from the jewelry, such as to a belt. The use of wires is acceptable for some items of jewelry, such as a brooch or necklace, but not for others, such as earrings or a tongue stud.
A xe2x80x9cbuttonxe2x80x9d battery, a small disc-shaped battery, typically employs the two flat faces of the disc as the contacts of opposite polarity. Because button batteries are small and relatively lightweight, they are obvious choices for jewelry mounted directly to the battery, so as to avoid long wires. For example, a tongue stud could be welded to one contact face of the battery. The stud could be inserted into a pierced tongue from below, the battery thus serving as the backing, and an illuminated decoration could attached from the front.
A problem with using a button battery in such a way is the risk of shock or burn to the person wearing the jewelry. The battery could corrode and short out after exposure to saliva or, if swallowed by mistake, to stomach acid. Even if used for an earring or other jewelry not worn in the mouth, a standard button battery can burn or shock a person. When a standard button battery does fail by shorting, the short is typically between points on the case.
There is a need for a battery that is safer than the well-known button battery to be used for jewelry or other devices used in close contact with the skin or mouth.
There is a need for a battery that is more resistant to corrosion, even if swallowed. There is a need for a battery that does not have the potential to burn skin if it shorts out Such a battery preferably would retain the small size, light weight, and smooth surfaces of a standard button battery.
This invention is a battery that is well suited for wearing on a person""s body to power illuminated jewelry or other small devices. The battery of the present invention is similar to a standard button battery in its appearance and shape
The present battery includes electrodes of opposite polarities, with one of the electrodes being enclosed within the case of the battery If the battery should fail by shorting between the electrodes, the short is inside the case and thus remote from the body.
In a preferred embodiment, the battery includes a bottom electrode, for example a cathode, forming the bottom face of the battery. The electrode of opposite polarity, for example an anode, is spaced above the cathode and the intervening space is filled with an electrolyte medium, such as a moist paste containing mobile ions
A cover encloses the electrolyte and the anode. The edge of the cover is attached to a lip on the periphery of the cathode to form a sealed can In one preferred embodiment, the cover is metal and electrically conductive, thus the cover serves as an extension of the cathode.
To allow the jewelry or other device to contact both electrodes, a small via passes through the cover, providing access to the anode The device to be operated by the battery preferably includes a co-axial stem conductor that can attach to the via The co-axial stem conductor has an internal rod that has a pointed tip, within a co-axial external tube that terminates above the tip of the internal rod. The internal rod and external tube are electrically isolated by insulation.
The illuminated jewelry is mounted onto the safety battery of the present invention by inserting the stem conductor into the via In a preferred embodiment, the via and the stem conductor have compatible threads for secure mounting.
The exposed tip of the internal rod contacts the anode when the jewelry is mounted in a fully engaged position in the via and the shorter external tube contacts the cover, which is at the same potential as the cathode.
A penetrable insulation medium isolates the anode from the cover The insulation medium prevents electrical shorting between the cover and anode and provides corrosion protection for the internal part of the battery The tip of the stem conductor penetrates the insulation medium to contact the anode.
When the jewelry is removed, the penetrable insulation xe2x80x9chealsxe2x80x9d, or closes on itself to seal the anode from corrosion. By protecting the anode from corrosion, the reliability and lifetime of the battery are increased. If the battery is accidentally swallowed, potentially toxic corrosion products are not released into the stomach.
Thus, the battery of the present invention is a safe and reliable means for powering small devices worn on the person, such as illuminated jewelry. The battery is designed such that it will not shock, burn, or poison a person, as other batteries can.
Other features and advantages of the invention will become more apparent upon a reading of the following detailed description, together with the drawings in which like reference numerals refer to like parts throughout.